Display screen or portion thereof with transitional graphical user interface



1. Display screen or portion thereof with transitional graphical user interface

1.1 : Front view, first image in sequence

1.2 : Front view, second image in sequence

The images sequentially transition from Figure 1.1 to Figure 1.2. The process or period in which an image transitions to another image forms no part of the claimed design.

The broken lines depict the display screen or portion thereof and form no part of the claimed design. The broken lines depict portions of the graphical user interface and form no part of the claimed design. The broken lines depict and electronic device and form no part of the claimed design. 

CLAIM The ornamental design for display screen or portion thereof with transitional graphical user interface, as shown and described. 